WATER ABSORBING RESIN POWDER PROCESS FOR PRODUCTION THEREOF AND USE THEREOF

摘要

The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polymerizing an unsaturated monomer; and drying the resultant crosslinked hydrogel polymer, wherein the water-absorbent resin powder has a crosslinked structure and a mass-average particle diameter of 300 to 600 mu m wherein the ratio of fine particles having particle diameters of not larger than 150 mu m is less than 10 mass % of the water-absorbent resin powder, with the production process being characterized by further comprising a magnetic-flux irradiation step of passing a magnetic field having a magnetic flux density of not less than 0.05 Wb/m<2> through the water-absorbent resin powder after the drying step in the production process.